1. Technical Field
The present disclosure relates to a design method of a freeform imaging system, especially a freeform imaging system with wide linear field-of-view (FOV).
2. Description of Related Art
Compared with conventional rotationally symmetric surfaces, freeform optical surfaces have higher degrees of freedom, which can reduce the aberrations and simplify the structure of the system in optical design. In recent years, with the development of the advancing manufacture technologies, freeform surfaces have been successfully used in the imaging field, such as head-mounted-displays, reflective systems, varifocal panoramic optical systems, and microlens arrays.
Traditional freeform imaging system design uses spherical or aspherical system as the starting point. Then, some surfaces in the system are replaced by freeform surfaces to obtain satisfactory results.